Knitting machine



Dec. 28 1926.

B. HOFFMAN KNITTING MACHINE Filed Feb.v 19,

1926 3 Sheets-Sheet l Dec. 28 1926. 1`,612,723

B. HOFFMAN KNITTING MACHINE Filed Feb. 19. 1926 5 Sheets-Sheet L Summa/43 Dec. 28 1926. 1,612,723

B. HOFFMAN KNITTING MACHINE Filed Feb. 19, 1926 3 Sheets-Sheet 5 l i U17-g5 I w 47 ,45 gmc/nto@ j Be/y'am/n Hoffman- Cil STTS

UNET

1,612,723 earner einen.

BENJAMN HOFFMAN, GE' SOUTH BELSIT, ILLINXS, ASSEGNOR TO FARAMOUNT TEK- TILE MACHINERY C0., OF CHICAGO, ILLNOS, A CORPORATION OF ILLINGXS.

KNITTING MACI'NE.

Application filed February 19,

This invention relates, primarily, to knitting machines; and it has particular reference to the type thereof in which the needle-v cylinder is raised and lowered to vary the length of stitch produced therein; and it involves a controlling-device therein for positively maintaining', in a predetermined position, mechanism that operates automatically to vary the length of the stitch in a course.

My inventive-concept-involving an attachment, in one aspect thereof-is especially applicable to circular knitting machines of the so-called Scott & Villiams type, as exemplified in VUnited States Patent No. 1,152,850, dated September 7, 1915, of R. lV. Scott, for knitting seamless hosiery.

In the accompanying drawings, I have illustrated one of many embodiments of the structure; but it is to be understood that my inventive-concept is susceptible of other embodiments and utilizations and also of a wide range of modiiication and variation without depart-ing from the principles of the invent-ion or sacrificing any of its salient and underlying features.

ln these drawings, which show the device applied to a machine of the type illustrated in the above-mentioned Scott patent:

Figure 1 is a view in vertical Section through the needle-cylinder, column. and sinlrer-cam-ring of the machine, with certain parts omitted more clearly to illustrate my controlling-device and its relation to other mechanisms of the machine;

Fig. 2 is a view in plan and somewhat fragmentary 5 Fig. 3 is a view in perspective of the device, showing its operating relation to the sinlier-cam-ring;

Figi: 4l is a fragmentary View, in central vertical section, of the device;.and

.lf 5 is an enlarged, Sectional view of the presser-element of the device.

ln the aforementicned Scott :Ks l"illiams tyihie of machine, certain parts thereof-such as the n et 1ifa-cylinder or larricr-hy reason of their arrangement, are capable of rotative and reciprocal movements with respect to a relatively tired base and actuating cams thereon that influence the action ofthe needles in the cylinder. The construction is such that the movable cylinder and its adjunctive parts may iioat, so to speak, with respect to the hase and cams. Due to this fact, it 'not infrequently occurs that, for one 1826. Serial No. 89,404.

or another of several reasons, the cylinder is not in its proper position and this varies to an extent that the needles carried thereby are caused to draw too much yarn, in consequence of which the fabric, at certain portions, is too loosely knit. lt will be evident that if this loosely-knit fabric occurs duringl the production of the ankle or instep sections of the stocking, an undesirable prodnct is produced.

Due to the law of operation of the machine, it seems to have been found essential to construct it so that the needle-cylinder and its adjunctive parts would tend to return toward their lowest positions by gravity and it is because of this that the ioating condition is liable to occur if and when gravity .is not suilicient to overcome the rei nce to movement of the parts. The cylinde. is pushed up positively by a column oliieiating under the influence of the patterndrum. lil/hen the position of this drum is changed 'to lower the cylinder, the column is free to fall by gravity, and the cylinder should follow it under the same influence. if, however, gravity of the parts is not, alone, suiiicientto overcome friction, etc., and insure that the cylinder shall assume the position determined by the cam-surface on the pattern-drum when the cylinder is being lowered for tightening the stitches, the present invention furnishes auXiliary means, acting in conjunction with gravity, to cause the cylinder to assume, constantly, the proper operatingl position when the action of the pattern-drum is to lower it and Without, in any way, preventing` the raising` of the cylinder when the tendency of the drum is to elevateit positively. i

Prior to my invention, no practical means (so far as l am aware) has been provided for insuring' proper positioning-1' of the cylinder and its needles duringl the stage ot shorteningy the stitches in the knitting operation, and the result has been that the fabric was sometimes looser than desired at such points. Various expediente have heen attempted, hut these have never been successful, so far as I am aware, and were, at best, mere maleshifts.

rihe device constitilting my invention has in practice, on the contr f', been operated most successfully' and ei'iiciently, with the result that ine normal tendency of the cylinder and its needles to vary from' a required position, with resultant loose knitting, is e'tlectually prevented.

`While l have herein disclosed the device as an attachment tor and applicable to a Scott & lill/illiams knitting machine, it is to be understood that l also contemplate building it in the structure as a permanent part of the machine and that it may also be utilized in conjunction with other makes ot machines.

lt is to be understood that the machine as herein illustrated includes, inter alia, a machine-frame 1; a cylinder-rotating mechanism including a gear 2; pattern mechanism comprising a pattern-drum 3; knitting instrun'ientalities comprisingl a needle-cylinder 4 and independentlyY movable needles 5 slidably supported therein; cylinder-elevating mechanism associatec` therewith and comprising a column G to which is attached one arm i' ot a two-arm lever 8, the other arm 9 or' which carries a series ot plunger-s 10 which cooperate with a series of cams 1l on the drum 3. i

lilncompassing the needle-cylinder is a cam-cylinder 12 which is stationary on the bed-plate 13 or' the machine.

The foregoing elements, comprising the gear 2, a sleeve 14 integral therewith and upon which the needle-cylinder 4 is removably mounted, and the cani-cylinder 12, are relatively stationary in a vertical sense. rfhe needle-cylinder, however, is vertically movable to adjust the length ot the stitch and for other purposes, as well as to be tree tor removal trom the machine.

To provide tor the vertical movement ot' the needle-cylinder, the gear 2 is bored through, as at 15 (Fig. 1) in three places, to receive three movable supports 16 in the torni ot' hard steel pins, all ot the same length. The bores 15 are in line with the bottom oil the needle-cylinder which freely rests upon the upper ends oi these pins.

rlhe pins 16 rest upon and, by reason ot the motion of the gear 2, rotate with respect to, a ring 18 at the top oit the column (S and having a suitably Jrormed anti-friction surface, this ring having a bearing` Within a depending cylindrical flange 19 o't' the bedplate 13. rlie ring 13 is vertically movable within said ring 19 by the vertical movement ot thc column (i concentric with the knitting axis which lits within the l'lange it) at its upper end and uponA which the ring 18 rests. As will now be evident, and as 'fully described in said patent, the adjustnient ot the needle-cylinder' by the means just described determines the length ot the .s itch formed b v each needle during the lniitting operation.

'the needle-cyliinler 4- is held to rotate with the sleeve 14 on the gear 2 by a feather 2O i ing inv a vertical keyway 21 on the inner l ot the cylinrler. 'ihe cylinder may thus be adjusted vertically with respect to the gear and sleeve 14 without disturbing its rotative adjustment with respect to the gear 2 or other elements of the machine.

Mounted on the upper end ot the needlecylinder is a web-holder ring or dial 22, and superposed thereon is a cam-ring 23 for operating web-holders 24, as usual, and as 't'ully explained in said Scott patent.

Detachably secured to the bed-plate 13, as by a holt is a bracket 26 formed with a transverse groove 27 adapted to receive the bed-plate 13, the latter, on its periphery, being preferably provided with two indentations 23 into which short screws 29 extend and which are threaded through the bracket 26. The screws and 29 serve to hold the bracket rigid on the bed-plate.

Pivoted in the upper end of the bracket is a two-armed member 30 comprising a body-portion 31 bored, as at 32, to receive a cross-pin 33. Each of the arms 34 of the member 30 is tormed with bosses 35 bored to receive a sliding-pin 36 having an enlarged lower end 37, tor purposes presently to be explained. The upper end ot the pin is threaded to receive a nut 3S and a locknut 39. Encircling the pin is a spring 40 bearing against the enlargement 37 and the upper end ot a recess 41 formed in the boss 35.

'lhreaded into the cross-pin 33 is a link 42 connected at its lower end to one end of a lever 43 fulcrumed at 44 on the bracket 26.

Means are associated with the device just described tor actuating it; such means, preterably and as shown, including a rod 45 which extends through the bed-plate 13 and, at its lower end, is pivotally connected to one part 46 ot a two-.part lever 47 tulcrumed at 48, the other part 49 of the lever being Yformed with a cam-engaging surface 50 adapted to ride on the tace of the drum 3 and to be engaged by cams 51 and 51a carried by the drum.

The upper end ot the rod contacts with the underside of an arm 52 forming a component of a switch-cam 53.

peration: The opera-tion of the structure above described will now be evident: TWhen the parte are in the position shown in Fig. l, each ot the headed pins 36 (which l shall herein call presser-elements) bears, with yielding` pressure, against the upper tace of the cam-ring` lllhen, however, the cam 51 on the pattern-drum 3, in the rotation thereof, disengages the end 50 of the lever 47, the latter' will be caused to rock on its fulcrum 48, thereby actuating` the rod 45 in a dowiiward direction and, by reason ot the tact that the tree end ot' the lever 43 is disengaged Jfrom a screw 54 otl a switch-camlinger the two-arm member 34 is rocked on its iulcrum. relieving the tension on the springs 40 which encircle the presser-elements. As soon as the extremity 50 of 'the portion 49 of the lever 4T is engaged by and rides up on cam 51a or 51, the lever Will be rocked in the opposite direction, causing the rod 45 to be raised and,'by reason of its engagement with the screw 54 in the switchcam-tinger 55 mounted on the upper end of the rod 45, the lever 43 is rocked on its fulcrum to operate the tivo-arm member and move the presser-elements against and with a yielding pressure upon the cam-ring.

During the movement of the two-arm member' in either direction, thecross-pin 33 has a short sliding movement in the bodyportion 31 of the member, this being necessary by reason of the position of the fulcrum of the lever with respect to the connection to the lever of the link 42.

The extent of movement of the two-arm member under the influence of the lever 43 may be varied by screwing the link 42 farther into or out of the cross-pin, as the case may be. l

The device, ust described, by reason of the yielding pressure which it imposes upon the cam-ring, produces a follow-up action on the ring A23, on the associated ring 22 and, through it, positions the needle-cylinder 4 downwardly. This, in turn, through the pins 16 and the ring 18, pushes the column 6 downwardly.l ln other Words, the device controls the cylinder which carries the Webholders over which the yarn is drawn. The length of each stitch is, of course, determined by the position of the knitting-ledge of the Web-holders or sinkers with respect to the usual stitch-cam-not herein shovvn-operatively associated with the needle-cylinder.

As already stated, gravity alone is not always sufficient to cause the cylinder to lower to the position in which the cams on the drum 3 are intended to place it when the stitches are being tightened. Various conditions contribute to prevent this: For insta-nce, the cylinder, during circular-Work, revolves at a high rate of speed, being driven by the gear 2 through its sleeve and the feather 20 Working in the keyivay 21; and, as the cylinder has considerable Weight, the driving-pressure on the surface of the feather is also considerable, so that, if the surfaces are not in perfect sliding condition, vertical movement of the cylinder would create friction which gravity, alone, might not he sufficient to overcome, especially in view ot' the inertia of the revolving cylinder. ln such rases, the cylinder will lag behind that point Where it should then be. It is at this stage that my device functions. It has a follow-up action, in that when in engagement with the cam-ring 23. it has a normal tendency to press it and the cylinder downwardly and, thus, supplements gravity in positioning the @lindern In consequence, all haelt-lash between the cylinder and the pattern-drum is taken up and, as a result, the

mechanism which operates automatically to vary the length of the stitch in any required course or courses is maintained in the predetermined position. As already stated, the two-arm member, with its presser-elements, is held against the cam-ring through the lever 43 and its connection With the rod 45 and adjunctive parts.

lllhen it is time for the cylinder to reciprocate, as in making the heel and toe oitl the stocking, the cam-ring must play between the limits required; and, under these circumstances it is desirable to relieve the cam-ring from the pressure exerted thereon by this device. lt is at this stage that the switch-cam has to be actuated, as Well understood; and, by reason of the connection of the device to the mechanism which controls the position of this switch-cam, the two-arm member is rocked on its ulcrum andraises it and thereby relieves the tension of the springs 40 on the presser-elements simultaneously with the switch-cam being brought into action. As the cylinder Will have been placed in the proper position before reciprocating knitting begins, and as the length of stitch required throughout the heel and toe Work during this reciprocation remains constant, it is unnecessary for the device to be in operation at that time and it is, there-fore, released in the manner described through the action of the switch-cam controlling mechanism. Furthermore, the driving pressure on the feather is continually being varied and relieved during reciprocation so that there is no driving pressure thereon at times and the cylinder is, then, free to fall by vgravity into its proper position. l If it becomes necessary to regulate the degree of pressure on the cam-ring by means of the device, the tension of the springs 40 may be varied by tightening or loosening the nuts 38 and 39 on the pin 36. At the same time, the link 42 may also be adjusted in the y cross-pin, as already referred to.

It is to be understood that my device constitutes one oi a plurality of means for positioning the cylinder and thereby el'i'ect a tightening of the stitch: rlhe weight of the parts vconstitutes one. means, and my device constitutes another and includes instrumentalities for relieving it periodically, as oreasion requires. 1 I

Vhat I claim is:

l. In a knitting machine, a needle-carrying cylinder, needles therein, Web-holders operatively associated therewith, af ringmember at the upper portion of the cylinder, and a follow-up device combinatively associated with and having a normal tendency to exert a downward yielding pressure on the ring-member te maintain the Webholders in a predetermim-id relation to the knitting-position of the needles.

il-'il lili) 2. In a knitting machine, a needle-carrying cylinder, needles therein, web-holders operatively associated therewith, a ring-member at the upper portion of the cylinder, a follow-up device combinatively associated with and having a normal tendency to exert a downward yielding pressure on the ringmember to maintain the web-holders in a predetermined relation to the knitting-position of the needles, and means for varying the relation of the device with respect to the ring-member.

3. In a knitting machine, a needle-carrying cylinder, needles therein, web-holders operatively associated therewith, a. ringmember at the upper portion of the cylinder, a follow-up device combinatively associated with and having a normal tendency to ei;- ert a Idownward yielding pressure on the ring-member to maintain the web-holders in a predetermined relation to the knitting-position of the needles, and means t'or varying the relation ot the device with respect to the ring-member periodically.

el. In a knitting machine, a needle-carrying cylinder, needles therein, web-holders operatively associated therewith, a ringmember at the upper portion ot' the cylinder, a follow-up device eombinatively associated with and having a normal tendency to exert a 'downward yielding pressure on the ring-member to maintain the web-holders in a predetermined relation to the knitting-position of the needles, and means for varying the relation of the device with respect to the ring-member periodically and automatically.

5. A knitting-machine including a needlecarrying cylinder having a plurality of operating positions, means for actuating the cylinder, means associated with the cylinder and having a normal tendency to maintain the same in a predetermined operating position` comprising a ring-member on the upper portion of the cylinder, a two-arm member, spring-controlled presser-elements carried by the two-arm member and yieldingly engageable with the ring-member, and actuating mechanism connected to the device for automatically varying its position.

6. A knitting-machine including a needlecarrying cylinder and a ring-member on the upper portion thereof, both the cylinder. and member' having a plurality of operating positions to vary the length of stitch, means associated with the member and having a normal tendency to maintain the same and the cylinder' in a predetermined operating position including a member carrying a spring-actuated. presser-element, and means tor automatically varying the action ot' the member periodically.

7. A knitting-machine including a needlecarrying cylinder, means ior actuating the cylinder to vary the length of stitch, a ringmember associated with the upper portion of the cylinder,y cam-operating mechanism also associated with the cylinder, a presserelement having a yielding engagement with the ring-member at av plurality ot points, and means interposed between the presserelement and the cam-operating mechanism whereby the former is actuated simultaneously with the latter.

8. A knitting-machine including a needlecarrying cylinder, means including a cam for actuating the cylinder to control the lengtl'i ot' stitch, a plurality of means for tighteningl the stitch, and means tor throwing stitch-tightening means out ot action periodically.

9. A knitting-machine including a needlecarrying cylinder, a ring-member associated with the upper portion of the cylinder, means including a cam for increasing the length ot stitch, a plurality ot means for tightening the stitch including a yielding device operatively associated with the cylinder and engageable with the ring member, means for automatically throwing the yielding device out of action with respect to the ring-member, and means for varying the yielding el'l'ect of the device.

l0. A knitting-machine including a needlecarrying cylinder, a ring-member on the upper portion thereof, a column associated therewith, means operating on the column to adjust the cylinder for varying the length ot stitch, and means operating directly on the ring member and independently of the column to depress the ring member and.

thereby the cylinder to move the cylinder in the opposite direction.

ll. A knitting-machine including a needlecarrying cylinder, means associated therewith for adjusting it to vary the length ot stitch, a ring-member on the upper portion of the cylinder, and means operating directly on the ring-member and having a normal tendency to counteract the cylinder-adjusting means whereby back-lash between the cylinder and the adjusting-means is controlled.

12. A follow-up device for attachment to knitting-machines including a bracket, machine-securing means carried thereby, a twoarm member pivoted on the bracket, springcontrolled presser-elements adjacent the ezitremities of the member, means for adjusting` the yielding action of the presser-elements, a lever ulcrumed onV the bracket, and an adjustable link between the lever and the member.

13. A follow-up device for attachment to lmitting-machines including a bracket, machine-securing means carried thereby, a twoarm member pivoted on the bracket, springcontrolled presser-elements adjacent the extremities of the member, means for adjustingthe yielding action of the presser-elene u.)

niente, a lever lulerumed on the lirm'vliet, and an :lidjuetahle connection between the lever and the nien'ilier.

M. A. linitting-n'iaehine including a needlecylinder, needles, a pattern-drinn for operating tlie cylinder and by Wliieli the length of eti teli is determined, and positioning means .including gravity for Causing the cylinder to deecend in reir-.tion to the drum, a ring- 10 member on the upper portion of the cylinder, Web-holders associated with the ringineniber, and nieans operating on the ringnieinlver and having a nernml tendency to exert a downward yielding pressure thereon to maintain the Web-holders in a predetern'iined relation to the knitting position of the needles.

In testimony whereof I alix my signature.

BENJAMIN HOFFMAN. 

